Steam-heated piston.



E. H. LUIJEMANP STEAM HEATEQ PISTON.-

APPLICATION FILED FEB. 8| I911.

Patented D00, 11, 1917:

lift

dti

tilii IlElJVTIIS-l' H. LUDEMAJW, 015 NEW YORK, Ya

srnamnnarnn meta.

specification. of Letters Patent.

application filed February 8, 1917. Serial no. 147,473.

To (ZZZ whom it may concern: 1

lie it known that l, EDWIN H. LUDEMAN,

a citizen of the United iitates, residing at New York, in the county of New York and titate of New York, have invented certain new and useful improvements in Steamlrlteated Pistons, of which the following is a specification.

.lIn steam engines, particularly those of the unitlow type, that is, in which exhaust ports are located about the middle of the cylinder and are controlled by the piston, the value of a steam heated piston has been demonstrated, and it is the object of the present invention to provide improved means for heating the piston, especially the faces thereof agaii'ist which the steam impinges when it is let in througlrthe inlet valves. This object may be effected by steam inlets to the piston which register with a steam supply pipe at the end of each stroke, and this may be done without the use of a hollow tail. or piston rod, or other inconvenient devices.

The invention may be embodied in various forms, of which one is illustrated in the accompanying drawing, in which Figure 1 is a longitudinal section of a uniflow engins provided with the improvement. Fig; 2 IS a cross section on the hue 22 of Flgul.

lihe cylinder of the engine is illustrated in the drawings at 6 and is shown provided with steam inlets 7 at opposite ends, which will be controlled by suitable valves in a known manner. About the middle of the cylinder it is provided with a double row of exhaust ports 8 which communicate with a double uniflow exhaust belt 9. There is thus produced a bridge or closed space 10 between the exhaust ports, the purpose of which is to provide a place for the opening of a steam supply pipe 11, through which live steam is supplied, from any suitable source, to the interior of the piston. The same result could be attained in other ways, the essential points being that a steam sup ply pipe shall open through the wall of the cylinder in such position that it may register with a port in the piston at some time, and be covered and closed by the piston at other times, and be closed off from the cylinder space at all times.

its shown, each end or head of the piston has a cored or annular chamber 12, with a port 13 located in such position that it will register with the open pipe 11 at the end of the piston stroke, whereby steam will be ad mitted into the said chambers 12, with the result of heating the ad acent walls of the] piston. Thetwo end chambers may be connected by a pipeor passage 1 1 to distribute the steam to both chambers.

The pipe 11, andthe ports 13, are preferably placcdat the bottom of-the cylinder where the weight, of the piston holds it in close contact with the cylinder wall, whereby leakbetween the surfaces will be pre vented." Or additional means may be used. to prevent such leak, such as packing set in the wall; around the ports.

For drainage, and to provide a circula tion, a small drain port 16 relocated near the bottom of the chambers 12 in position to register with a drain port and pipe 17, leading off fromrthe cylinderyand this may be provided with a valve 18 to let ofi" condensation when desired.

Itwill be noticed that the inlet portsliti tothe steam chambers in the piston, as well as the drain ports 16, are located on such line, or in such positions, that they will not cross the main outletports 8, but will pass oyer the: bridges between the same, so that no undesirable escape of steam from the chambers willtake place, and, except when registering with the corresponding pipes, all the pipes and ports will be closed against the steam in the cylinder and the exhaust, the piston being long enough to lap the pipes at the end of each stroke, one or the other set of main exhaust ports being nevertheless uncovered at the end of the stroke. The heated surfaces of the piston prevent initial condensation and otherwise assist economical and efficient operation.

The invention is not limited to the exact embodiment shown, but various modifications may be made within the scope of the following claims.

I claim:

1. The combination with a steam engine cylinder and a long hollow piston, the cylinder having inlet ports at opposite ends, and exhaust ports controlled by the piston, of a steam supply pipe having an opening through the wall of the cylinder independent of said inlet ports, the piston having a port which registers with said opening to admit steam to the interior of the piston at some time in its stroke, and which piston covers and closes the opening at all other times, said port being out of communication Patented cc. it, 1917.

with the said inlet and exhaust ports at all times.

2. The combination with a unifiow steam engine cylinder and hollow piston, the cylinder having inlet ports at opposite ends, and exhaust ports controlled by the piston and arranged at opposite sides of the middle line of the cylinder, of a steam supply pipe having an opening through the cylinder wall distant from said inlet ports and between said exhaust ports, whereby the piston always laps said opening, and said piston having a port which registers with said opening at the end of its stroke, said port being out of communication with said inlet and exhaust ports at all times.

'3. The combination with a steam engine .cylinder having exhaust ports at opposite sides of the middle line thereof, with a part of the cylinder wall bridged between said ports, of a hollow piston adapted to alternately uncover said ports at the ends of opposite strokes, and which laps said bridged part at all times, and a steam supply pipe opening through said bridged part, the pis ton having aport near its end which registers with said pipe at the end of stroke to admit steam into the piston.

l. The combination with a steam engine cylinder having exhaust ports at opposite sides of the middle line thereof, with a part of the cylinder wall bridged between said ports, of a hollow piston adapted to alternately uncover said ports at the ends of opposite strokes, and which laps said bridged part at all times, and steam supply and drain pipes opening through said bridged part, the piston having inlet and drain ports which register with said pipes at the end of stroke to permit steam to flow through the piston.

5. The combination with a steam engine cylinder having a double row of exhaust ports with a space between bridged by the cylinder wall, and a supply pipe for heating fluid opening through said bridged part, or a hollow piston adapted to alternately uncover each row of exhaust ports at the ends of opposite strokes, said piston having an inlet port to the interior thereof, said port r registering with said supply pipe opening at about the end of stroke and covering the same at other times.

6. The combination with a steam engine cylinder having a double row of exhaust ports with a space between bridged by the cylinder wall, and a supply pipe for heating fluid opening through said bridged part, oil a hollow piston adapted to alternately uncover each row of exhaust ports at the ends of opposite strokes, said piston having an inlet port to the interior thereof, said port registering with said supply pipe opening at about the end of stroke and covering the same at other times, and means to drain said heating fluid from the interior of the piston.

In testimony whereof, I ailix my signature in presence of two witnesses.

EDWIN H. LUDEMAN.

Witnesses MARIE A. BITTER, DAVID H. REID.

7 Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, I). S. 

